Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

We've been using the paint method to do boards for a few months now, and it's been working pretty well. If you need top-notch detail, then you need to go with a photoresist solution. 10mil/10mil is pretty easy to do repeatably.

The key thing to remember that the laser is about 8mil wide. This will affect the width of the traces and isolation that you lay out, because you'd end up with less and more, respectively.

We have noticed the re-adhesion behavior mentioned below, but if you reduce the paint to the minimum needed for coverage, the amount of airborne burnt-off paint will be correspondingly reduced. Burning from the far side of the board probably couldn't hurt. We clean lasered boards gently with IPA and a cotton ball before etching.

We've gone from bare copper clad board to etched-undrilled in about 30 minutes with fresh etchant (FeCl). Assuming that you have access to a laser printer, the ease+cost can't be beat (you might be able to do cheaper by hand-drawing or plotting with a resist pen though). But you won't be running two traces in between 0.1"-centered holes either, so there's still a place for photoresist in the world.

We haven't done any soldermasking, but if you find something that works well for you, let us all know.

-eric